I hope that everyone here is going to celebrate on June 20, 2003. That's when US Patent 4,558,302 [patft.uspto.gov] expires. That is the patent that Unisys has on the LZW compression algorithm that is used in GIFs.
Did you know that you may owe money to Unisys? If you used unlicensed software to produce GIFs, they could send you a bill or sue you.